1. Field
Embodiments relate to a compound for an optoelectronic device, an organic light emitting diode including the same, and a display including the organic light emitting diode.
2. Description of the Related Art
A photoelectric device is, in a broad sense, a device for transforming photo-energy to electrical energy, or conversely, a device for transforming electrical energy to photo-energy.
An organic photoelectric device may be classified as follows in accordance with its driving principles. One type of organic photoelectric device is an electron device driven as follows: excitons are generated in an organic material layer by photons from an external light source; the excitons are separated to electrons and holes; and the electrons and holes are transferred to different electrodes from each other as a current source (voltage source).
Another type of organic photoelectric device is an electron device driven as follows: a voltage or a current is applied to at least two electrodes to inject holes and/or electrons into an organic material semiconductor positioned at an interface of the electrodes; and then the device is driven by the injected electrons and holes.
As examples, the organic photoelectric device may include an organic light emitting diode (OLED), an organic solar cell, an organic photo-conductor drum, an organic transistor, an organic memory device, etc., that uses a hole injecting or transporting material, an electron injecting or transporting material, or a light emitting material.
For example, an organic light emitting diode (OLED) has recently drawn attention due to an increase in demand for flat panel displays. In general, organic light emission may refer to transformation of electrical energy to photo-energy.
The organic light emitting diode may transform electrical energy into light by applying current to an organic light emitting material. The organic light emitting diode may have a structure in which a functional organic material layer is interposed between an anode and a cathode. The organic material layer may include multiple layers including different materials from each other, e.g., a hole injection layer (HIL), a hole transport layer (HTL), an emission layer, an electron transport layer (ETL), and an electron injection layer (EIL), in order to help improve efficiency and stability of an organic light emitting diode.
In such an organic light emitting diode, when a voltage is applied between an anode and a cathode, holes from the anode and electrons from the cathode may be injected to an organic material layer. The generated excitons may generate light having certain wavelengths while shifting to a ground state.
Recently, it is has become known that a phosphorescent light emitting material may be used for a light emitting material of an organic light emitting diode, in addition to the fluorescent light emitting material. Such a phosphorescent material may emit lights by transiting the electrons from a ground state to an exited state, non-radiance transiting of a singlet exciton to a triplet exciton through intersystem crossing, and transiting a triplet exciton to a ground state to emit light.